What is everyones thoughts on using overboard dumps on your headers, so they drain when the engines are tuned off? I've read pros and cons to this. Con is that the water drains out and may not allow the header to cool properly when the engines are off. Pro is obvious, if there is ever a leak, the water drains out the back of the boat, not into the the engine.

I drain not permanet as the heat probs and when start after short time again cold water will go to heatet headers.Dont like this. After the run is over real i drain then.Michael

I agree, that is a good point about cold water in a hot pipe. I was thinking about adding a solenoid system, so I can just flip a switch at the end of the day, and dump the water. Are the ball valves that you have mounted on the front or the back of the header?

At the backside.I drain them in the V from underwater exhaust as i have mounted this in my boat.
At single engine no problem ti drain so.
At 2 Motors maybe an electric vent is easier.Michael

I fitted a time delay to a solenoid valve for a guy, we had a N/O 12 volt valve that was closed as soon as the ignition was switch on and the timer was set for 120 mins after ignition was switched off. Got the parts off amazon for a grand total of $60 CAD. I mounted the timer in a small plastic box and potted it, that was over five years ago and still working.

Just google timed relay and they will show up in your search.

I might be interested in that. How much would you want per kit?

And what material are the vents?
At time i found no ones that work long in saltwater!Michael

I used a setup much like this a while back but for restricting the water flow in the header to try to keep the 02 alive